Approximately thirty percent of the body protein of mammals is comprised of collagen, a long rod-like polypeptide containing three parallel chains of coiled-coil structure with a molecular weight of about 300,000. Collagen existing in skin, cartilage, bone and tendon is composed of two .alpha.1 chains and one .alpha.2 chain of roughly one thousand amino acids each. The .alpha.1 sequence is completely known and substantial sequences of the .alpha.2 chain have been elucidated.
Collagenase effects an ultra-specific cleavage of collagen at a site one quarter the length of the molecule from the C-terminus in each of the three chains.
Collagenase is produced by rheumatoid synovial cells at a rate higher than it is produced by normal cells and the destructive events of rheumatoid arthritis can be correlated with the generation of collagenase. Collagenase has also been found to be involved in disease states resulting in tissue destruction of the stomach, eye, middle ear, peridontal membranes and skin. The administration of a collagenase inhibitor to prevent tissue destruction is an indicated method of treatment for disease states involving proteolytic destruction of collagen.
Collagenase is a metallo enzyme of molecular weight about 40,000 with a requirement of zinc. The enzyme is known to be inhibited by chelating agents such as ethylenediaminetetraacetic acid, o-phenanthroline, penicillamine and disulfide reducing agents such as cysteine and dithiothreitol as well as a number of poorly characterized naturally occurring substances.